clair088

Continuing with the topic of T helper cell “shapeshifting,” Hirahara et al. report on the complexity of environmental determinants and epigenetic factors that orchestrate T helper cell plastic responses ( Journal of Allergy and Clinical Immunology 2013; 131(5):1276-1287 ).   The authors discuss the regulatory and metabolic factors that affect the plastic capabilities of helper T cells.   Beginning with an excellent overview of the current taxonomy of Th cells, Hirahara et al. reviews the current understanding of CD4 T cell fate and their homeostatic interactions within T helper cell lineages.   Further discussion addresses the idea of “signature” transcription factors and cytokine production in T cell lineages.   The authors question the accuracy and usefulness of this static characterization in light of the accumulating knowledge of T helper cell capacity for expression of multiple transcription factors and cross-family cytokines under the influence of different p...

Lloyd and Saglani present us with a new perspective on T cells as major players in asthma genesis this month ( Journal of Allergy and Clinical Immunology 2013; 131(5):1267-1274 ). They discuss the classic Th2 model of asthma, and then begin to probe the inconsistencies that have arisen around this paradigm in light of current research and new therapeutics. Lloyd and Saglani focus on current knowledge of the heterogeneity of asthma phenotypes, the lung epithelium interface, and the less than expected efficacy of new, Th2-targeted therapies to frame their discussions about the various types of effector T cell subsets including classic Th2 cells, Th17 and -22 cells, T regulatory cells, and the novel Th9 subset. The authors emphasize, where relevant, that T cell cytokines are now known to be associated with non-immune cell sources, such as the lung epithelium, and that is an important predicator of effector response. In fact, many T cell-related cytokines have both positive and negati...